"HAVE A glass of champagne," says Lennox Cato, "and mind where you put it." He's joking, of course, but then I wouldn't want to be the one spilling champers on his beautiful, Chinese-style, ebony chest of drawers.

Lennox is an exhibitor at the Olympia Fine Art and Antiques Fair, a showcase of past treasures. On offer are beautiful walnut cabinets, old master paintings and plenty of curios, including a wild gothic chair with a frame made entirely of antlers. It's just like the Antiques Road Show, but everything is for sale - albeit at a price.

There was a time, in the Sixties, when people only wanted the new. Victorian relics, in particular, were slung on the skip or left to gather dust in attics. This has all changed. Antiques are seriously big business, as Lennox, the only black dealer in Britain's top antique association, confirms.

"There is a lot of psychology involved in selling antiques," he says. "That's why we've got this champagne, to help people relax. You are talking about people spending a lot of money, thousands of pounds on a single item, so it's important to make them feel reassured, although you mustn't be overly familiar."

The woman, quite rightly, declines to hold the delicate artefact, says she will think about it and walks off. "She can definitely afford it," says Lennox. "But as a private collector she'll want a really good think and have a good look round before she buys."

Huge amounts of money changes hand at this creme de la creme of antique fairs, but for window shoppers keen to glimpse another, more refined past world, the atmosphere remains relaxed.

London dealer Alasdair Brown, with 14-years trade experience, was quite happy for me to lie and gently bounce on an pounds 8,500 four-poster bed, a fine example of the 19th-century arts and crafts movement, apparently. "It's rather comfortable isn't it," he says as I lie prostrate on top of the late 18th-century counterpane.

The most expensive thing Edric Van Vredenburgh has on his stall is a table made almost entirely from ivory, priced, because it's so rare, at pounds 240,000.

Edric, who also has two tarnished mirrors on display, "because some people like them like that", describes his clients as "the international set with serious money. We don't get many Middle Eastern buyers because they tend to go for glitzy gilded pieces," he says.

The current apple of Edric's eye is a collection of 18th and 19th-century beetles preserved in 40 glass boxes and making a startling if slightly disconcerting wall display, if you have pounds 18,000 to spare. "I've been cleaning them all week by hand," he says.

"Most dealers tend to have a profit margin of between 40 and 50 per cent, although this varies depending on where you buy the piece in question," Edric explains.

With stalls costing around pounds 10,000 a throw, or pounds 300 a square metre, there is no question that a dealer's outgoings are high, although it is questionable whether private collectors really get a good run for their money. But then the serious buyers probably aren't short of a bob or two.

"Will you excuse me a second," says Edric leaving me to finger a pair of horn cups, "I'm just going to have a word with one of the wealthiest men in the world." The wealthiest man and his beautifully manicured American wife, appear to have done business with Edric before. They greet each other like old friends and are soon in deep conversation about some walnut table or other.

The antiques world is slightly unreal. Few people would have room to display four life-sized, classical, 17th-century gods - Italian, very rare - or even want to part with pounds 58,000 for a pair of serpentine commodes.

But there is another side to the market. Robert Pugh is a ruddy-faced Welshman specialising in a native farmhouse look. "No," he says, "most of our wares are not bought by the Welsh, they are not big on the distressed farmhouse look."

Americans and Kensington dwellers who want an urban country cottage look are his main customers. And with 18th-century patchwork quilts from pounds 300, this is the more affordable if less glamorous end of the antiques market.

Back to Lennox, who seems to have done a roaring morning's trade with the aid of his champagne. "The Brits still aren't really into serious antiques," he says. "They prefer to spend their money on holidays or new cars or little pieces, although we are doing our hardest to change all that."

The Olympia Fine Arts and Antiques Fair is open until 14 June. For more information, call 0171 370 8186.